This invention relates to machines that fill containers, such as plastic bags, with liquid material, such as food products, and, more specifically, to a filling head mechanism of such a machine and its cooperation with a container spout.
Many liquid or semi-liquid food products are distributed in bags of various sizes, typically carrying from one to six gallons of material. These bags are usually made of flexible plastic sheet material, with a rigid plastic spout attached. The bag is both filled and emptied through the spout. An advantage of this type of container over a rigid container is that, as product is removed through the spout, the bag collapses around the remaining product. This is a particular advantage with food products, since spoilage is retarded by minimizing contact of the bag contents with air. A wide variety of food products are carried in such containers, including soft drink syrups, and condiments, such as mayonnaise, catsup, and the like.
Machines used to fill such containers with product most commonly feed a long strip of empty bags to a bag separating station, then advance individual bags one at a time to a fill station, where they are filled with liquid product, and then move the filled bag out of the fill station. A bag is filled by coupling its spout with a filling head or nozzle, passing product through the filling head into the bag, and, after a valve in the filling head has stopped the flow of product, separating the bag spout from the filling head. A cap is usually then placed on the spout of the filled bag by snapping it in place, and the bag is then ready for shipping.
With such filling machines, it is difficult to avoid leaving some of the product in and around the spout of the filled bag, resulting in product remaining on the outside of the spout around the cap. Further, product often drips from the filling head onto the spout and outside of the bag itself as the filling head and bag spout are separated after filling. The resulting mess on the outside of the spout and bag is usually undesirable, particularly when the product is sticky, soft drink syrup being an example, or has a high viscosity, mayonnaise being an example. Distribution and use of such messy bags can be very unpleasant. Besides being sticky to the touch, the presence of food product on the outside of the container can develop an unpleasant odor and support the growth of bacteria. Others have sought to wash the filled bags to remove product from their outside but it is difficult to remove sticky and viscous materials from plastic surfaces.
Therefore, it is a primary object of the present invention to provide a filling machine, and a method of filling a container such as a bag, that avoids leaving product on the outside of the spout or container.